Treatment of a MyD88 inhibitor alleviates rejection and inflammation in xenotransplantation by inhibiting dendritic cells activation and trained immunity in macrophages.

BACKGROUND: Acute vascular rejection (AVR) and systemic inflammation in xenograft recipients (SIXR) negatively impact the xenografts survival, and novel immunosuppressants are required to improve survival outcomes. We previously reported that TJ-M2010-5, a myeloid differentiation factor 88 (MyD88) inhibitor, exerts excellent anti-rejection effects in allogeneic transplantation. The aim of the present study was to evaluate the efficacy of TJ-M2010-5 in preventing AVR and SIXR and to investigate whether combined treatment of TJ-M2010-5 with anti-CD154 antibody (MR1) could prolong xenograft survival furthermore. METHODS: A model involving heart transplantation from Sprague-Dawley rats to BALB/c mice was established in vivo, and the xenografts developed typical AVR. Bone marrow-derived dendritic cells and macrophages were cultured to study the underlying mechanisms induced by rat cardiomyocyte lysate stimulation in vitro. RESULTS: TJ-M2010-5 monotherapy prolonged xenograft survival, although combination treatment with MR1 further enhanced the anti-AVR and anti-SIXR effects with about 21 days graft survival, compared to monotherapy. TJ-M2010-5 reduced dendritic cell and macrophage activation induced by xenotransplantation, downregulated CD80/CD86 expression, suppressed B-cell activation and anti-donor antibody generation, reduced pro-inflammatory cytokine production and tissue factor expression, and attenuated epigenetic modifications underlying interleukin-6 and tumor necrosis factor-α production in macrophages by inhibiting nuclear factor kappa B nuclear translocation. CONCLUSIONS: TJ-M2010-5 attenuated AVR and SIXR and contributed to xenograft survival by inhibiting dendritic cell and macrophage activation. A dual-system inhibition strategy combining TJ-M2010-5 with anti-CD154 antibody achieved better results in xenotransplantation.

The role of pyroptosis in hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is the main histologic type of liver cancer. It accounts for the majority of all diagnoses and deaths due to liver cancer. The induction of tumor cell death is an effective strategy to control tumor development. Pyroptosis is an inflammatory programmed cell death caused by microbial infection, accompanied by activation of inflammasomes and release of pro-inflammatory cytokines, interleukin-1ß (IL-1ß), and interleukin-18 (IL-18). The cleavage of gasdermins (GSDMs) promotes the occurrence of pyroptosis leading to cell swelling, lysis, and death. Accumulating evidence has indicated that pyroptosis influences the progression of HCC by regulating immune-mediated tumor cell death. Currently, some researchers hold the view that inhibition of pyroptosis-related components may prevent the incidence of HCC, but more researchers have the view that activation of pyroptosis exerts a tumor-inhibitory effect. Growing evidence indicates that pyroptosis can prevent or promote tumor development depending on the type of tumor. In this review, pyroptosis pathways and pyroptosis-related components were discussed. Next, the role of pyroptosis and its components in HCC was described. Finally, the therapeutic significance of pyroptosis in HCC was discussed.

The Novel MyD88 Inhibitor TJ-M2010-5 Protects Against Hepatic Ischemia-reperfusion Injury by Suppressing Pyroptosis in Mice.

BACKGROUND: . With the development of medical technology and increased surgical experience, the number of patients receiving liver transplants has increased. However, restoration of liver function in patients is limited by the occurrence of hepatic ischemia-reperfusion injury (IRI). Previous studies have reported that the Toll-like receptor 4 (TLR4)/myeloid differentiation factor 88 (MyD88) signaling pathway and pyroptosis play critical roles in the development of hepatic IRI. METHODS: . A mouse model of segmental (70%) warm hepatic IRI was established using BALB/c mice in vivo. The mechanism underlying inflammation in mouse models of hepatic IRI was explored in vitro using lipopolysaccharide- and ATP-treated bone marrow-derived macrophages. This in vitro inflammation model was used to simulate inflammation and pyroptosis in hepatic IRI. RESULTS: . We found that a MyD88 inhibitor conferred protection against partial warm hepatic IRI in mouse models by downregulating the TLR4/MyD88 signaling pathway. Moreover, TJ-M2010-5 (a novel MyD88 inhibitor, hereafter named TJ-5) reduced hepatic macrophage depletion and pyroptosis induction by hepatic IRI. TJ-5 treatment inhibited pyroptosis in bone marrow-derived macrophages by reducing the nuclear translocation of nuclear factor kappa-light-chain-enhancer of activated B cells, decreasing the release of high-mobility group box-1, and promoting endocytosis of lipopolysaccharide-high-mobility group box-1 complexes. CONCLUSIONS: . Inhibition of MyD88 may protect the liver from partial warm hepatic IRI by reducing pyroptosis in hepatic innate immune cells. These results reveal the mechanism underlying the development of inflammation in partially warm hepatic IRI and the induction of cell pyroptosis.

Liraglutide attenuates intestinal ischemia/reperfusion injury via NF-κB and PI3K/Akt pathways in mice.

AIMS: Previous studies have reported that glucagon-like peptide-1 (GLP-1) may play a critical role in the development of intestinal ischemia-reperfusion (I/R) injury. The present study aimed to investigate whether liraglutide (GLP-1 analog) protects against intestinal I/R injury and reveals the possible underlying mechanism. MAIN METHODS: Temporary superior mesenteric artery occlusion was performed to establish an intestinal I/R injury mouse model. Different doses of liraglutide were administered in vivo. Then, the survival rate of mice exposed to different ischemia times, the histopathology, intestinal barrier index, cytokine production, intestinal tissue apoptosis, and the levels of several proteins were detected in each group. KEY FINDINGS: Pretreatment with liraglutide significantly alleviated the pathological changes induced by I/R and increased the overall survival of mice exposed to intestinal I/R injury. Moreover, liraglutide attenuated neutrophil infiltration of intestinal tissues, pro-inflammatory cytokine production (including IL-1ß, IL-6, and TNF-α), and apoptosis of intestinal tissues caused by intestinal I/R injury. In addition, liraglutide inhibited the nuclear translocation of nuclear factor-κB (NF-κB) and up-regulated the phosphorylation levels of phosphoinositide 3-kinase (PI3K) and protein kinase B (Akt) in the I/R group. SIGNIFICANCE: Liraglutide may attenuate the inflammatory response and the apoptosis of intestinal tissues via the NF-κB and PI3K/Akt pathway, protecting against intestinal I/R.

TJ-M2010-5 Attenuates Severe Myocardial Ischemia/Reperfusion Injury in Heart Transplantation by Inhibiting MyD88 Homodimerization In Vivo.

Survival of transplanted hearts is often limited by cold ischemia time. Here, we assessed the effects of the small molecular compound TJ-M2010-5 on graft preservation. In a cardiac cold ischemia/reperfusion model, TJ-M2010-5 ameliorated myocardial ischemia/reperfusion injury (MIRI) in histidine-tryptophan-ketoglutarate (HTK) organ preservation solution. When applied in HTK solution and on donors/recipients respectively, TJ-M2010-5 exerted optimal effects when applied as an additive in the HTK solution. TJ-M2010-5-administered mice exhibited shorter rebeating time; higher beating score; stronger and more regular sinus heart rate; and amelioration of apoptosis, inflammatory reactions, and myocardial injury. Mechanistically, TJ-M2010-5 inhibited the expression of key molecules in the toll-like receptor (TLR) signaling pathway and affected downstream proteins by inhibiting myeloid differentiation factor 88 homodimerization, thereby decreasing myocardial injury. Thus, TJ-M2010-5 may exert protective effects against MIRI by blocking the TLR signaling pathway. Our findings may lead to novel approaches for organ preservation, thereby reducing organ abandonment and improving recipient prognosis. The role of the TLR signaling pathway in MIRI progress and operation procedure of the MIRI model in vivo are presented in a graphical abstract (Online Abstract Figure).

TJ-M2010-5, A self-developed MyD88 inhibitor, attenuates liver fibrosis by inhibiting the NF-κB pathway.

Liver fibrosis is the result of most chronic inflammatory liver damage and seriously endangers human health. However, no drugs have been approved to treat this disease. Previous studies showed that the Toll-like receptors (TLRs)/myeloid differentiation factor-88 (MyD88)/nuclear factor-κB (NF-κB) pathway plays a key role in liver fibrosis. TJ-M2010-5 is a self-developed small molecule MyD88 inhibitor, which has been proven to have a good protective effect in a variety of inflammatory disease models. In the present study, to investigate the anti-fibrotic effect of TJ-M2010-5, mice were injected with carbon tetrachloride (CCl4) in vivo and LX2 cells (a human hepatic stellate cell line) were treated with TGF-ß1 in vitro to induce liver fibrosis. In vivo studies showed that TJ-M2010-5 attenuated the CCl4-induced liver damage, collagen accumulation, and the activation of hepatic stellate cells by inhibiting the nuclear transfer of NF-κB. Moreover, in vitro experiments of LX2 cells stimulated with TGF-ß1 further indicated that the NF-κB pathway is involved in the development of liver fibrosis. TJ-M2010-5 significantly inhibited the proliferation and activation of LX2 cells. In addition, TJ-M2010-5 upregulated the expression of bone morphogenetic protein and membrane-bound inhibitor (BAMBI) in LX2 cells by blocking the activation of MyD88/NF-κB, thereby inhibiting the phosphorylation of Smad2/3 and the expression of collagen I (COL1A1) induced by TGF-ß1. In conclusion, this study illustrates the anti-hepatic fibrosis effect of TJ-M2010-5 and provides a new treatment method for liver fibrosis.

TJ-M2010-5, a novel CNS drug candidate, attenuates acute cerebral ischemia-reperfusion injury through the MyD88/NF-κB and ERK pathway.

Background: Cerebral ischemia-reperfusion injury (CIRI) inevitably occurs after vascular recanalization treatment for ischemic stroke. The accompanying inflammatory cascades have a major impact on outcome and regeneration after ischemic stroke. Evidences have demonstrated that TLR/MyD88/NF-κB signaling contributes to CIRI. This study aimed to investigate the druggability of MyD88 in the central nervous system (CNS) and the neuroprotective and anti-neuroinflammatory effects of the MyD88 inhibitor TJ-M2010-5 on CIRI. Methods: A middle cerebral artery occlusion (MCAO) model was used to simulate CIRI in mice. BV-2 cells were stimulated with oxygen glucose deprivation/reoxygenation (OGD/R) or lipopolysaccharide, and SH-SY5Y cells were induced by OGD/R in vitro. Neurological deficit scores and cerebral infarction volumes were evaluated. Immunofluorescence staining was performed to measure neuronal damage and apoptosis in the brain. The anti-neuroinflammatory effect of TJ-M2010-5 was evaluated by analyzing the expression of inflammatory cytokines, activation of microglia, and infiltration of peripheral myeloid cells. The expression of proteins of the MyD88/NF-κB and ERK pathway was detected by Simple Western. The concentrations of TJ-M2010-5 in the blood and brain were analyzed by liquid chromatography-mass spectrometry. Results: The cerebral infarction volume decreased in mice treated with TJ-M2010-5, with the most prominent decrease being approximately 80% of the original infarction volume. Neuronal loss and apoptosis were reduced following TJ-M2010-5 treatment. TJ-M2010-5 inhibited the infiltration of peripheral myeloid cells and the activation of microglia. TJ-M2010-5 also downregulated the expression of inflammatory cytokines and inhibited the MyD88/NF-κB and ERK pathway. Furthermore, TJ-M2010-5 showed good blood-brain barrier permeability and no neurotoxicity. Conclusion: TJ-M2010-5 has an excellent therapeutic effect on CIRI as a novel CNS drug candidate by inhibiting excessive neuroinflammatory responses.

Inhibition of MyD88 by a novel inhibitor reverses two-thirds of the infarct area in myocardial ischemia and reperfusion injury.

Cardiomyocytes, macrophages, and fibroblasts play important roles in inflammation and repair during myocardial ischemia/reperfusion injury (MIRI). Myeloid differentiation primary response 88 (MyD88) is upregulated in immunocytes, cardiomyocytes, and fibroblasts during MIRI. MyD88 induces the secretion of proinflammatory cytokines, including interleukin (IL)-1ß, IL-6, and tumor necrosis factor alpha (TNF-α), while fibroblasts are recruited and activated to mediate cardiac remodeling. The aim of this study was to assess the anti-MIRI effect and mode of action of the novel MyD88 inhibitor TJ-M2010-5. We synthesized TJ-M2010-5 and identified its target by co-immunoprecipitation, after which we established a murine MIRI model and tested the protective effect of TJ-M2010-5 by immunohistochemistry, flow cytometry, real-time PCR, and western blotting. Neonatal rat cardiomyocytes subjected to anoxia/reoxygenation were also isolated and their supernatants used to stimulate cardiac macrophagocytes and fibroblasts in vitro. MyD88 was found upregulated during the early and late phases after MIRI. The MyD88 inhibitor considerably improved cardiac function, reduced cardiomyocyte apoptosis, reduced IL-1ß, IL-6, and TNF-α secretion, and inhibited CD80+CD86+MHCII+ macrophage and fibroblast migration. Moreover, TJ-M2010-5 markedly inhibited Toll-like receptor/MyD88 signaling in vivo and in vitro. Thus, our findings highlight TJ-M2010-5 as a potential therapeutic agent for MIRI treatment.

The MyD88 inhibitor TJ-M2010-2 suppresses proliferation, migration and invasion of breast cancer cells by regulating MyD88/GSK-3ß and MyD88/NF-κB signalling pathways.

MyD88 has been implicated in the tumourigenesis, metastasis and recurrence of breast cancer (BC). Here we utilized TJ-M2010-2 (TJ), an inhibitor of MyD88 homodimerimerization, and siMyD88 to suppress the function of MyD88 in MCF-7 and MDA-MB-231 cells. BC cells were treated in vitro and xenografted into nude mice to generate a model in vivo. TJ inhibited BC cell growth by impeding proliferation rather than by promoting apoptosis in vitro. Additionally, TJ and siMyD88 significantly attenuated cell migration and invasion, inhibited EMT-like progression and reduced cytokine (IL-6, IL-8, TGF-ß1 and TNF-α) secretion induced by LPS. In vivo, TJ significantly hindered tumour growth in mice. Notably, TJ also decreased the secretion of IL-6, IL-8, TGF-ß1, and TNF-α and M2 macrophage infiltration in the tumour microenvironment. The expression of MyD88, TRAF6, NF-κB p65, Snail, MMP-2, MMP-9, p-GSK-3ß and p-Akt was significantly downregulated by TJ in BC cells and tumour tissues. Collectively, these results suggest that a MyD88 inhibitor (TJ) may be a promising therapeutic modality for treating BC patients.

TJ-M2010-5, a novel MyD88 inhibitor, corrects R848-induced lupus-like immune disorders of B cells in vitro.

B cell hyperactivities are involved in the development of systemic lupus erythematosus (SLE). Toll-like receptor 7 (TLR7) in the B cells plays a pivotal role in the pathogenesis of SLE. Previous studies have focused on the intrinsic role of B cells in TLR7/MyD88 signaling and consequently on immune activation, autoantibody production, and systemic inflammation. However, a feasible treatment for this immune disorder remains to be discovered. The in vitro cellular response that have been studied likely plays a central role in the production of some important autoantibodies in SLE. We successfully used R848 to build a lupus-like B cell model in vitro; these B cells were overactivated, differentiated into plasma cells, escaped apoptosis, massively proliferated, and produced large amounts of autoantibodies and cytokines. In the present study, we found that TJ-M2010-5, a novel MyD88 inhibitor previously synthesized in our lab, seemed to inhibit the lupus-like condition of B cells, including overactivation, massive proliferation, differentiation into plasma cells, and overproduction of autoantibodies and cytokines. TJ-M2010-5 also induce B cells apoptosis. Furthermore, TJ-M2010-5 was found to remarkably inhibit NF-κB and MAPK signaling. In summary, TJ-M2010-5 might correct R848-induced lupus-like immune disorders of B cells by blocking the TLR7/MyD88/NF-κB and TLR7/MyD88/MAPK signaling pathways.

Human MiR-4660 regulates the expression of alanine-glyoxylate aminotransferase and may be a biomarker for idiopathic oxalosis.

BACKGROUND: Dysfunction of oxalate synthesis can cause calcium oxalate stone disease and inherited primary hyperoxaluria (PH) disorders. PH type I (PH1) is one of the most severe hyperoxaluria disorders, which results in urolithiasis, nephrocalcinosis, and end-stage renal disease. Here, we sought to determine the role of microRNAs in regulating AGXT to contribute to the pathogenesis of mutation-negative idiopathic oxalosis. METHODS: We conducted bioinformatics to search for microRNAs binding to AGXT, and examined the expression of the highest hit (miR-4660) in serum samples of patients with oxalosis, liver tissue samples, and determined the correlation and regulation between the microRNA and AGXT in vitro. RESULTS: MiR-4660 expression was downregulated in patients with oxalosis compared with healthy controls (84.03 copies/µL vs 33.02 copies/µL, P < 0.0001). Moreover, miR-4660 epigenetically decreased the expression of AGT in human liver tissues (Rho = - 0543, P = 0.037). Overexpression of miR-4660 in HepG2 and L02 cell lines led to dysregulation of AGXT at both the mRNA (by 71% and 81%, respectively; P < 0.001) and protein (by 49% and 42%, respectively; P < 0.0001) levels. We confirmed the direct target site of miR-4660 binding to the 3'UTR of AGXT by a luciferase assay. CONCLUSION: MiR-4660 is probably a new biomarker for mutation-negative idiopathic oxalosis by regulating the post-transcription of AGXT, providing a potential treatment target of mutation-negative idiopathic oxalosis.

Short-term use of MyD88 inhibitor TJ-M2010-5 prevents d-galactosamine/lipopolysaccharide-induced acute liver injury in mice.

Excessive activation of the TLR/MyD88 signaling pathway contributes to several inflammation-related diseases. Previously, our laboratory synthesized a novel thiazaol-aminoramification MyD88 inhibitor named TJ-M2010-5. In this study, we interrogated the role of MyD88, as well as the protective effect of TJ-M2010-5, in a d-gal/LPS-induced acute liver injury mouse model. In order to induce acute liver injury, BALB/c mice received intraperitoneal injection of d-gal and LPS at a dose of 800 mg/kg and 80 µg/kg body weight, respectively. All mice died within 48 h of injection without intervention. However, pre-treatment with TJ-M2010-5 as well as knock-out (KO) of the MyD88 gene significantly improved mouse survival rate to 73.3% and 80% at 48 h, respectively, and both treatments protected liver function. These pathological results demonstrated that TJ-M2010-5 and MyD88 KO reduced the infiltration of inflammatory cells and protected hepatocytes against apoptosis. Furthermore, TJ-M2010-5 remarkably inhibited NF-κB and MAPK signaling in vivo. LPS-induced activation of macrophages as well as pro-inflammatory factors were also shown to be decreased after TJ-M2010-5 treatment in vivo and in vitro. Taken together, these results suggested that blockage of the TLR/MyD88 signaling pathway by TJ-M2010-5 has an important role in the prevention of inflammation-related acute liver injury.

A Novel Inhibitor of Homodimerization Targeting MyD88 Ameliorates Renal Interstitial Fibrosis by Counteracting TGF-ß1-Induced EMT in Vivo and in Vitro.

BACKGROUND/AIMS: The TLR/MyD88/NF-κB signaling pathway has been successfully used to treat renal interstitial fibrosis (RIF). However, the exact therapeutic mechanism is still unknown. Here, we assessed the therapeutic efficacy of TJ-M2010-2, a small molecular compound that inhibits MyD88 homodimerization, in RIF induced by ischemia reperfusion injury (IRI). METHODS: In vivo, RIF was induced in mice by IRI, and the mice were prophylactically treated with TJ-M2010-2. In vitro, HK-2 cells were incubated with TGF-ß1 to induce EMT, and the cells were pretreated with TJ-M2010-2. RESULTS: We found that, compared with the IRI group, the TJ-M2010-2 group showed marked attenuation of RIF and renal function injury; decreased expression of TGF-ß1, α-SMA, vimentin, MMP2 and MMP9; and increased E-cadherin expression. Furthermore, TGF-ß1-induced EMT was blocked by TJ-M2010-2 in HK-2 cells, as evidenced by blocked morphologic transformation, restored E-cadherin expression and inhibited α-SMA expression. In addition, compared to the TGF-ß1 group, the TJ-M2010-2 group showed profound inhibition of the expression of TRAF6, p65 and Snail and upregulation of the expression of IκBα. CONCLUSION: This MyD88 inhibitor may be a potential therapeutic agent to ameliorate RIF.